For soldiers, tiny may be big in solving battlefield power needs

As troops move across an unforgiving battlefield, individual soldiers carry an array of advanced electronic devices, powered by heavy, cumbersome batteries, which often need to be replaced on a daily basis. It has been reported that during Operation Iraqi Freedom, battery supplies barely met the demand.

Certainly the electronic devices--which include computers, radios, laser sights, night vision displays, global positioning systems and environmentalsensors--provide a competitive edge, but the U.S. armed forces are looking for ways to lighten the load.

For several years, Battelle researchers at Pacific Northwest National Laboratory have worked with the U.S. Army to develop small, lightweight power sources. About a year ago, the effort became a joint Army-Navy program for the Army's Communications-Electronic Command and the U.S. Marine Corp's Expeditionary Program. The principal researchers are Matt Donnelly, Jamie Holladay and Daniel Palo.

Through this work, scientists are developing a fuel cell power system designed to produce about 100 watts of energy for recharging batteries and powering small electronic devices. The system, which should be complete in about two years, will use methanol fuel, a Battelle-developed fuel processor and a proton exchange membrane fuel cell to produce electricity. When developed, the unit will be about the size of a half-gallon container of ice cream. Eventually these small power systems will be transitioned to run on other hydrocarbons such as butane, propane and kerosene-based JP-8 fuel for the military.

Before delivering the final technology, Program Manager Chip Larson said there will be several intermediate steps or objectives.

In March 2004, for example, researchers will provide a small suitcase-sized version of the system that will still be portable, but will not offer optimized capabilities. Continuing optimization and miniaturization efforts will follow, bringing the device down to the size of a shoe box. In the third and final year, the system will be further fine-tuned, reduced in size and made more rugged for military use.

According to Larson, "The system will require minimal operator intervention. All the soldier will have to do is keep it fueled."

One of the prime advantages of such a power source is that there will be no need for the soldiers to carry hydrogen, nor will the military have to store and transport the gas. "Our plan is to produce a system where methanol goes in one end and electrons come out the other," Larson said. "Methanol is flammable, but it is certainly much easier to manage than hydrogen."

Development of the system will rely on multiple capabilities, including microtechnology, advanced catalysts, new sensor technologies and smart systems. In addition, a key focus of the effort is to ensure that the finished system uses as many "off-the-shelf" components (pumps, fans and other parts) as possible. "These power systems will have to be built in large quantities at some point in the future, so we are making sure that the parts we use, where possible, are commercially available or can be adapted from commercial parts. We don't want a situation where parts have to be made by a researcher in a laboratory," Larson explained.

Although initially the power system will be used to recharge batteries, it's envisioned that the technology will evolve into a power supply that is integrated with equipment used by soldiers.

"Most everyone agrees that the soldier of tomorrow is going to be carrying more electronics. Today, troops carry about five electronic devices and some experts believe that number will grow to eight or nine over the next decade," Larson said.